Art of Problem Solving: Algebraic Expressions Number Game

Art of Problem Solving's Richard Rusczyk explains simplifying expressions with a number game.

[yurongli]

Edward Z said:
IT DOES NOT WORK WORK WITH ONE
1+3=4
4+2(1+7)=4+2*8=4+16=20
20-3(1-2)=20-3(-1)=20+3=23

[Becca-dd]

Oh, and I started with 7, which is my favorite number. Let me know if it's right!

[yurongli]

You guys, can you tell me what number you used?

[cobbiliu]

what if you use a decimal, like 0.5, then you get 14.

[indiabiologyexplains]

it does not work with any negative number

[hongjinzhou]

I did -3 because that is my fave, but i got -7

[M_Chen]

Mine is -3-. 4:22 WHY DON'T YOU BELIEVE ME, RICHARD :(